Man Charged in Terrorist Probe After Suspect Shot Dead in Boston

A suburban Boston man was held without bond Wednesday on charges that he conspired with Usaamah Abdullah Rahim, a terrorism suspect who was fatally shot by police Tuesday.

David Wright, 24, also known as Dawud Sharif Abdul Khaliq, was arrested Tuesday night at his home in the Boston suburb of Everett. He was charged with conspiring with Rahim to destroy evidence of Rahim's alleged plots to kill law enforcement officers either Tuesday or Wednesday and to behead an unidentified person in another state.

Wright faces a probable cause hearing June 19. The FBI said in a criminal affidavit that the evidence he conspired to destroy was Rahim's smartphone, which carried records of calls between the two men and text messages in which Rahim described his plots in guarded language.

Rahim been under investigation and surveillance for several weeks by the Boston Joint Terrorism Task Force, according to the FBI affidavit. A senior official told NBC News that officers were investigating whether Rahim had become radicalized by ISIS-inspired social media messages and that they feared a terrorist plot was in the works.

Officials are reviewing whether Tuesday's shooting was justified, but early surveillance video and witness statements indicate that the officers' "lives were in danger," Boston Police Commissioner William Evans told reporters.

Shawn Henry, a former FBI official, said the ISIS network's use of social media remains one of the biggest recruitment tools for ISIS and other groups hoping to gain a foothold and following in the West.

"Those who have been inspired historically through the web are now being bantered by social media, Twitter, etc.," Henry said on TODAY, "and it's causing huge concern for law enforcement and the FBI."